Commit-ID: 3c646f2c6aa9e918d7fc77867df7f430059f9ccc Gitweb: http://git.kernel.org/tip/3c646f2c6aa9e918d7fc77867df7f430059f9ccc Author: NeilBrown <neilb@xxxxxxx> AuthorDate: Sun, 17 May 2015 15:19:34 +1000 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Mon, 18 May 2015 17:23:47 +0200 genirq: Don't suspend nested_thread irqs over system suspend Nested IRQs can only fire when the parent irq fires. So when the parent is suspended, there is no need to suspend the child irq. Suspending nested irqs can cause a problem is they are suspended or resumed in the wrong order. If an interrupt fires while the parent is active but the child is suspended, then the interrupt will not be acknowledged properly and so an interrupt storm can result. This is particularly likely if the parent is resumed before the child, and the interrupt was raised during suspend. Ensuring correct ordering would be possible, but it is simpler to just never suspend nested interrupts. Signed-off-by: NeilBrown <neil@xxxxxxxxxx> Cc: GTA04 owners <gta04-owner@xxxxxxxxxxxxx> Cc: Kalle Jokiniemi <kalle.jokiniemi@xxxxxxxxxxxxxxx> Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20150517151934.2393e8f8@notabene.brown Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> --- kernel/irq/pm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c index 5204a6d..d22786a 100644 --- a/kernel/irq/pm.c +++ b/kernel/irq/pm.c @@ -123,6 +123,8 @@ void suspend_device_irqs(void) unsigned long flags; bool sync; + if (irq_settings_is_nested_thread(desc)) + continue; raw_spin_lock_irqsave(&desc->lock, flags); sync = suspend_device_irq(desc, irq); raw_spin_unlock_irqrestore(&desc->lock, flags); @@ -163,6 +165,8 @@ static void resume_irqs(bool want_early) if (!is_early && want_early) continue; + if (irq_settings_is_nested_thread(desc)) + continue; raw_spin_lock_irqsave(&desc->lock, flags); resume_irq(desc, irq); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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